1. Technical Field
The invention relates to a semiconductor device, and is a technology applicable to, for example, a semiconductor device including a diode.
2. Related Art
Among semiconductor devices, there is one integrating a control circuit which generates a control signal of a power control element. In such a semiconductor device, a power supply voltage of the power control element is higher than a power supply voltage of the control circuit. Therefore, a second control circuit may be provided between the control circuit and the power control element to input the control signal to the power control element. Generally, a power supply voltage of the second control circuit is equal to or lower than the power supply voltage of the power control element and is higher than the power supply voltage of the control circuit. Therefore, it is necessary to generate the power supply voltage of the second control circuit separately from the power supply voltage of the control circuit.
A high-withstand voltage diode is used for a circuit that generates the power supply voltage of the second control circuit. For example, Japanese Unexamined Patent Application Publication No. 2012-4460 discloses a diode having the following structure. First, an n-type epitaxial layer is formed on a p-type substrate. In addition, a p-type layer and an n+ layer that is connected to a cathode electrode are provided in the n-type epitaxial layer. In addition, a p+ layer that is connected to an anode electrode is provided in the p-type layer. A withstand voltage of the diode is determined by a distance between the n+ layer and the p-type layer.